Integrated multi-chamber heat exchanger

ABSTRACT

A one-piece heat exchanger manufactured using an additive manufacturing process is described. The heat exchanger includes a plurality of channels formed therein. At least some of the plurality of channels may be configured to provide structural support to the heat exchanger to reduce its weight. Different coolant media may be used in a first set and a second set of the plurality of channels to provide different types of cooling in an integrated one-piece heat exchanger structure.

BACKGROUND

Heat exchangers are used in products across many industries includingthe military, automotive, and electronics industries to preventoverheating of components when the components are in operation. A heatexchanger provides temperature regulation by transferring heat away fromheat-generating components located near and/or coupled to the heatexchanger. The heat exchanger includes materials with high thermalconductivity, which transfer heat away from the components and into acoolant (e.g., air, water) circulating through the heat exchanger, whichtransports the heat away from the components to prevent overheating.

SUMMARY

Some embodiments are directed to a heat exchanger. The heat exchangercomprises a one-piece body and a plurality of channels formed in theone-piece body, wherein at least some of the plurality of channels forma lattice having layers of repeating shapes in a first dimension of theone-piece body, wherein the repeating shapes of the lattice havesuccessively-smaller dimensions across the layers in the first dimensionof the one-piece body.

Other embodiments are directed to a method of manufacturing a heatexchanger. The method comprises forming, using an additive manufacturingprocess, a one-piece body and a plurality of channels formed therein,wherein at least some of the plurality of channels form a lattice havinglayers of repeating shapes in a first dimension of the one-piece body,wherein the repeating shapes of the lattice have successively-smallerdimensions across the layers in the first dimension of the one-piecebody.

Other embodiments are directed to a method of cooling a component with aheat exchanger. The method comprises arranging the heat exchangeradjacent to the component, wherein the heat exchanger comprises aplurality of channels, wherein at least some of the plurality ofchannels form a lattice having layers of repeating shapes in a firstdimension of the heat exchanger, wherein the repeating shapes of thelattice have successively-smaller dimensions across the layers in thefirst dimension.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, allcombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should also be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning most consistentwith the particular concepts disclosed herein.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures is represented by a like numeral. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1 shows a cross-section through a conventional heat exchangerincluding a plurality of fins forming a rectangular pattern;

FIG. 2 shows a cross-section through a heat exchanger including aplurality of channels in accordance with some embodiments;

FIG. 3 shows an alternate channel design for a heat exchanger inaccordance with some embodiments;

FIG. 4 shows an additional alternate channel design for a heat exchangerin accordance with some embodiments;

FIG. 5 shows a cross-section through a heat exchanger having a channelpattern with repeating elements of different sizes in accordance withsome embodiments;

FIG. 6 shows a zoomed in version of some of the channels in the channelpattern of FIG. 5 in accordance with some embodiments;

FIG. 7 shows a three-dimensional representation of a heat exchanger inaccordance with some embodiments;

FIG. 8 shows the heat exchanger of FIG. 2 configured to provide multipletypes of cooling using different coolant media in accordance with someembodiments;

FIG. 9 shows a perspective view of a heat exchanger in accordance withsome embodiments;

FIG. 10 shows an alternate view of the heat exchanger of FIG. 9;

FIG. 11 shows a cross-section view through the heat exchanger of FIG. 9;

FIGS. 12A and 12B show manifold flow patterns for a first coolant mediaflowing through a first set of channels and a second coolant mediaflowing through a second set of channels, respectively, in accordancewith some embodiments;

FIG. 13 shows a heat exchanger including a plurality of mountingstructures in accordance with some embodiments;

FIG. 14 shows a side view of the heat exchanger of FIG. 13 illustratingthe channel pattern;

FIG. 15 shows an alternate view of the heat exchanger of FIG. 13;

FIG. 16A shows an alternate design of a heat exchanger in accordancewith some embodiments;

FIG. 16B shows a view of the internal structure of the heat exchanger ofFIG. 16A;

FIG. 16C shows a cross-section view through the heat exchanger of FIG.16A; and

FIG. 17 shows a flowchart of a process for manufacturing a heatexchanger in accordance with some embodiments.

DETAILED DESCRIPTION

Some conventional heat exchangers are fabricated using techniques thatrequire the use of expensive equipment that operates at hightemperatures. Other fabrication techniques that use lower temperaturestypically produce heat exchangers with poorer thermal conductivity dueto the bonding materials used during the fabrication process. Theinventors have recognized and appreciated that conventional techniquesfor fabricating heat exchangers may be improved by using an additivemanufacturing process that produces a one-piece heat exchanger structurethat does not use conventional brazing or bonding techniques. The use ofadditive manufacturing also enables the fabrication of heat exchangershaving channel designs that are not possible or practical using otherfabrication techniques, as discussed in more detail below.

FIG. 1 schematically illustrates a cross-section through an example of aconventional heat exchanger 100 in which thin fins 110 form arectangular pattern between an upper base plate 120A and a lower baseplate 120B. The fins 110 are bonded to the upper base plate 120A and thelower base plate 120B by bonding layers 130A and 130B, respectively.Fins 110 may be made of any suitable material or materials having a highthermal conductivity. For example, fins 110 may be made of aluminum oranother suitable metal. A coolant (e.g., air) is passed through thechannels 140 formed by the rectangular pattern of the fins 110. Heatgenerated from a component located adjacent to the heat exchanger istransferred via one or both of the upper and lower base plates to thefins 110 having a high thermal conductivity. The heat is then furthertransferred to the coolant in channels 140 and is carried away toprevent overheating of the component.

Bonding of fins 110 to the upper and lower base plates is oftenperformed using a molten solder bath or vacuum brazing process in whichmetal-based braze interface materials are used at high-temperatures(e.g., 300C to 1100C) to attach the fins to the base plates. However,such processes are expensive, time-consuming, and have the potential forlatent corrosion. An alternative process for bonding fins 110 to thebase plate(s) is to use epoxies or other organic (e.g., polymer-based)interface materials. Using organic bonding materials provides a simplerbonding process than bonding using metal-based brazing due, in part, tolower curing temperatures (e.g., 100C to 150C). However, the bond formedby the organic interface materials generally has poor thermalconductivity resulting in a heat exchanger with poorer thermalconducting properties than heat exchangers fabricated using brazing.Although some organic bonding materials may include highly-conductiveparticles (e.g., alumina, boron nitride, diamond dust, silver, gold,aluminum) to improve the thermal conductivity of the materials, thethermal conductivity of such materials remains inferior to themetal-based brazing process described above.

The inventors have recognized and appreciated that conventionalprocesses for manufacturing heat exchangers may be improved by usingadditive manufacturing (e.g., 3D printing) techniques, which result in aone-piece construction for the heat exchanger that does not require theuse of fixtures, fasteners, or the bonding techniques described above.By not using bond interface materials the thermal conductive propertiesof the heat exchanger are improved, and the costs and time-delayassociated with conventional brazing techniques are reduced. Inparticular, additive fabricated metal alloys have a substantially higherthermal conductivity compared to organic bond material. Additionally,the use of additive manufacturing to create a heat exchanger enables thecreation of new heat exchanger designs that incorporate structuralsupport within the channel design itself and/or allow for multiple typesof coolant media to be used within a single heat exchanger, as discussedin more detail below.

Additive manufacturing techniques are used to fabricate a 3D structureby building up consecutive thin layers of a material (e.g., metal alloy)based on a 3D design for the structure specified in an electronic file.A wide variety of shapes can be fabricated using additive manufacturing.However, designs that include unsupported overhangs (e.g., overhang 150shown in FIG. 1) cannot be produced using additive manufacturing withoutthe incorporation of additional supporting structures used duringfabrication, and that may remain or be removed after fabrication. Whensuch supporting structures are removed after fabrication the structuralintegrity of the overhangs may be compromised. Accordingly, the abilityof additive manufacturing techniques to produce orthogonal structures,such as the repeating rectangular structure shown in FIG. 1, whichincludes unsupported overhangs, is limited.

The inventors have also recognized and appreciated that additivemanufacturing enables the fabrication of channel designs in heatexchangers that are not practical or possible using conventionaltechniques for manufacturing heat exchangers, including the brazing andbonding techniques discussed above. For example, additive manufacturingallows for the use of internal lattice structures, which cannot bemachined from solid material. As discussed in more detail below,additive manufacturing may be used to create entirely- orpartially-self-supporting channels for a heat exchanger that do not haveunsupported overhangs and do not require the use of separate supportstructures (e.g., upper base plate 120A or lower base plate 120B).

The design flexibility afforded by the use of additive manufacturingalso enables an optimization of one or more factors in designing a heatexchanger including, but not limited to, size, weight, channel wallstiffness, power cooling capacity, and manufacturing cost. Additionally,intricate manifold structures may be incorporated within the heatexchanger using additive manufacturing to enable more complex control ofcoolant flow in the channels of the heat exchanger.

FIG. 2 shows a schematic illustration of a cross-section through a heatexchanger 200 in accordance with some embodiments. Heat exchanger 200includes a plurality of diamond-shaped channels 210 that replace therepeating rectangular channel design of FIG. 1. The diamond-shapedchannels 210 do not include unsupported overhang sections and thus donot necessarily require additional support structures when fabricatedusing additive manufacturing. Depending on the particular shape of thechannel used, some support may be necessary to reinforce sides of one ormore of the channels. For example, in some embodiments, one or more ofupper triangle channels 220 or lower triangle channels 230 may be filledwith supporting material to reinforce the structure of diamond-shapedchannels 210. Additionally, or alternatively, one or more upper trianglechannels 220 and/or lower triangle channels 230 may be filled withcoolant to provide a single-mode or multi-mode heat exchanger, asdiscussed in more detail below.

The heat exchanger channels designed in accordance with some embodimentsof the invention may have any suitable dimensions. For example, in oneimplementation the dimensions of the sides of diamond-shaped channels210 may be 0.106 inches and the dimensions of the triangle channels 220,230 may be 0.106×0.106×0.146 inches with a channel wall thickness of0.015 inches. It should be appreciated that these dimensions areprovided merely for illustration and any suitable channel dimensions andchannel shapes may alternatively be used.

The channel pattern in heat exchanger 200 includes diamond-shapedchannels having sides oriented at 45°. However, diamond-shaped channelshaving other orientations may also be used. FIG. 3 illustrates across-section though a heat exchanger 300 having an alternative channeldesign in which the pitch of the sides of diamond-shaped channels 310 issteeper than 45°. Such a design increases the number of diamond-shapedchannels 310, upper triangle channels 320, and lower triangle channels330 in the repeating pattern for a heat exchanger having the same lengthas the heat exchanger shown in FIG. 2.

The channel designs illustrated in FIGS. 2 and 3 incorporate the samechannel element (e.g., diamonds and triangles) repeated across thelength of the heat exchanger. However, channel designs for a heatexchanger in accordance with embodiments are not so limited, and anysuitable channel design that provides adequate support for the channelsin the design may alternatively be used. FIG. 4 illustrates anotherchannel design in which two different diamond-shaped channels (e.g.,wide-diamond channels 410 and narrow-diamond channels 415) alternateacross the length of the heat exchanger. Upper triangle channels 420 andlower triangle channels 430 may correspondingly take any suitable shapeand may be filled with solid material to provide structural support ormay be unfilled, as described above.

Other shapes and patterns for channel designs for use in heat exchangersin accordance with some embodiments are also possible. For example,although diamond and triangle-shaped channels are described herein,other shapes including, but not limited to, hexagons, pyramids, circles,and ovals, may also be used. In some embodiments, the shape and/orpattern of channels in the heat exchanger may be determined based, atleast in part, on the type of coolant used, the amount of coolantdesired, the number of different types of coolant used in the heatexchanger, the pressure of the coolant used in the channels, the amountof fill support required, any other suitable factor, or any combinationof these factors.

As discussed above, some embodiments include at least one channel filledwith a solid material to provide support for other channels of the heatexchanger. For example, at least some of the upper or lower trianglechannels shown in FIGS. 2-4 may be filled with solid material to providesupport for the diamond-shaped channels of the heat exchanger. Theinventors have recognized and appreciated that the fill volume of theheat exchanger may be reduced by including additional channels within atleast some of the channels to increase the number of available channelsfor coolant as well as providing additional structural stability to thechannel design. Although the structures at least partially filled inwith solid material are referred to as “channels” herein, it should beappreciated that when fabricated using additive manufacturing, nochannel is actually formed. Rather, solid material is formed in layerswhere the channel would have been fabricated.

FIG. 5 illustrates a cross-section through a heat exchanger 500 having aplurality of channels arranged in a repeating structure along the lengthdimension of the heat exchanger and also in a direction orthogonal tothe length dimension. Heat exchanger 500 includes a pluralitydiamond-shaped channels 510, upper triangle channels 220, and lowertriangle channels 230 forming a repeating pattern along the lengthdimension of the heat exchanger. As shown, each of the upper trianglechannels 220 includes multiple layers of successively-smallerdiamond-shaped channels and an uppermost layer of triangle channels.Diamond-shaped channels 512 form a first layer of smaller channels abovechannels 510, diamond-shaped channels 514 form a second layer of evensmaller channels above channels 512, and diamond-shaped channels 516form a third layer of even smaller channels above channels 514.

Adding additional channels improves the structural integrity of thechannel structures in the heat exchanger by providing an internallattice structure and provides additional flexibility in how coolantsmay be used in accordance with various embodiments. For example, asdiscussed in more detail below, heat exchangers in accordance with someembodiments may include multiple coolants, and each of the multiplecoolants may be housed in a set of channels having a particularconfiguration.

A fourth layer of triangle channels 518 is formed above channels 516. Insome embodiments, at least some of triangle channels 518 may be filledwith a solid material to form an interface control upper surface of heatexchanger 500. As shown, the interface control upper surface is asubstantially-flat surface. However, it should be appreciated that inother embodiments, the heat exchanger may include an interface controlsurface that is formed by one or more non-flat shapes. Filling in onlyan upper layer of triangles with solid material decreases thefill-for-support volume of the heat exchanger, which results in alighter heat exchanger design than if larger portions of the structure(e.g., upper triangle channel 220) was filled with solid material.

In some embodiments, more than a single upper row of channels may befilled with a solid material to provide additional support, if neededfor a particular application. In yet further embodiments, one or more ofthe channels filled with solid material may be only partially filledwith solid material to further reduce the weight of the heat exchanger.FIG. 6 shows an enlarged view of upper triangle channel 220 within whicha plurality of layers of successively-smaller diamond-shaped channelsare formed. As shown, the top layer of triangle channels 618 is filledwith solid material to provide a substantially-flat solid surface on oneside of the heat exchanger. To reduce the weight of the heat exchanger,one or more of triangle channels 618 includes a hollow portion providinganother channel 620 within triangle channel 618. As shown, the channel620 is formed as a diamond-shaped channel. However, it should beappreciated that any shape channel may be formed inside of the top layerof channel(s) 618, and embodiments are not limited in this respect.

In some embodiments, heat exchangers designed in accordance with someembodiments may include one or more mounting structures 630 attached tothe surface of the heat exchanger configured to mount the heat exchangerto another component to be cooled as shown in FIG. 6. For example,mounting structures 630 may be card guide rails or slots configured tobe connected to one or more electronic cards. Alternatively, mountingstructures may be configured to connect to any other heat source, andembodiments are not limited in this respect.

During the additive manufacturing process, the mounting structures 630may be formed as a continuous extension of the one-piece body of theheat exchanger such that one or more of the triangle channels 618 atleast partially filled with solid material transfers heat from themounting structures 630 to the solid material in the triangle channel tofacilitate heat transfer in the heat exchanger. Mounting structures 630may have any suitable dimensions and may be placed at any location alonga surface of the heat exchanger. For example, in one implementation thewidth of mounting structures 630 is 0.018 inches and the mountingstructures are formed directly above every other triangle channel 618.Additional examples of heat exchangers including mounting structures 630are discussed in further detail below.

Although four repeating layers of shapes (e.g., diamonds) withsuccessively-smaller dimensions are shown in FIG. 5, it should beappreciated that any suitable combination of shapes and dimensions mayalternatively be used, and the design shown in FIG. 5 is merely oneimplementation. For example, a number of layers less than or greaterthan four may alternatively be used, and embodiments are not limited inthis respect. Additionally, other types of shapes including, but notlimited to, hexagons, pyramids, circles, and ovals, may instead be used.

FIG. 5 illustrates that the same repeating pattern may be used along theentire length dimension of heat exchanger 500. In other embodiments,different patterns of channels may be used at different locations alongthe length dimension of the heat exchanger. FIG. 7 illustrates a heatexchanger 700, designed in accordance with some embodiments, thatincorporates different patterns of channels along a length dimension ofthe heat exchanger. As shown, heat exchanger 700 includes acentrally-located diamond shaped channel 710. The upper-left triangle ofheat exchanger 700 includes a channel structure similar to thatdescribed in connection with FIG. 5. In particular, the channelstructure in the upper-left triangle comprises a plurality of levels ofsuccessively-smaller diamond-shaped channels. The top level of trianglechannels 718 are shown filled with a solid material to provide asubstantially-flat solid surface 720.

The inventors have recognized and appreciated that additivemanufacturing enables the creation of heat exchangers that may includechannels formed in any direction of the heat exchanger includinghorizontal channels, vertical channels, channels formed at an angle, orany combination thereof. For example, the upper-right triangle of heatexchanger 700 includes a channel structure different than the channelstructure in the upper-left triangle. As shown, the upper-right triangleis filled with a solid material along the length direction of the heatexchanger, and a plurality of vertical channels 740 are formed in theright side portion of the heat exchanger. Vertical channels 740 areshown as rectangular channels. However, it should be appreciated thatany shape of channels may alternatively be used including, but notlimited to the repeating shape channel structure shown in the upper lefttriangle channel of heat exchanger 700.

Any suitable material may be used to form the walls of channels in aheat exchanger in accordance with the techniques described herein,provided that the material is compatible with additive manufacturing.For example, the material used to form the channels may include, but isnot limited to, metal, ceramic, glass, carbon-based materials (e.g.,diamond), or any other suitable material that provides sufficient heattransfer for a particular heat exchange application.

Additionally, any suitable coolant or coolants may be used inconjunction with the heat exchangers described herein. For example, anyfluid or combination of fluids (e.g., various mixtures, emulsions orslurries of different fluids, compounds and/or particles) may be usedincluding fluids in liquid or gas state, or phase change material (e.g.,heat pipe, paraffin), capable of absorbing and transporting heat. Othercooling fluids such as liquid nitrogen, outgassing of solid carbondioxide, refrigerated and compressed air, ammonia, antifreeze,polyalphaolefin (PAO) coolant, etc., may also be utilized in conjunctionwith various embodiments, as the aspects are not limited in thisrespect.

Some conventional heat exchangers are configured to provide single-modecooling by using air, liquid, or some other coolant as a heat transportmedium to provide thermal regulation, as discussed above. Multi-modecooling may be provided by attaching multiple single-mode cooling heatexchangers together. However, multi-mode heat exchangers formed from acombination of multiple independent single-mode cooling heat exchangersare bulky and have a reduced thermal efficiency at the interface betweenthe single-mode heat exchangers. For example, a fluidic heat exchangerattached to an independent heat exchanger that incorporates phase-changematerial requires both more volume and suffers from a poor thermalinterface between the two single-mode heat exchangers.

The inventors have recognized and appreciated that the use of channeldesigns for heat exchangers in accordance with some embodiments,provides for the use of multiple unmixed coolants within the sameintegrated (e.g., one-piece construction) heat exchanger structure. Useof multiple unmixed coolants in an integrated heat exchanger structurereduces thermal efficiency losses and/or reduces the heat exchangervolume compared to multi-mode heat exchangers consisting of multipleconnected single-mode heat exchangers, as discussed above. FIG. 8 showsan embodiment of an integrated multi-mode heat exchanger in whichdiamond-shaped channels 810 are filled with a first coolant (e.g.,water) and triangle-shaped channels 820 are filled with a second coolant(e.g., air). Some embodiments include multiple fluid coolants havingdifferent properties such that heat transfer between channels (e.g., airto liquid, liquid to liquid) improves the cooling properties of a heatexchanger for a particular application.

As discussed above, the use of additive manufacturing to produce heatexchangers in accordance with the techniques described herein providesfor substantial flexibility in designing channel designs for heatexchangers having any suitable number and shape of channels. Anextension of this flexibility is the ability to optimize the proportion,size, shape, and/or spatial arrangement of channels for each of multiplecoolants in the integrated heat exchanger structure. For example, thechannel design pattern shown in FIG. 8 has a 1:1 ratio between thevolume of channels for the first coolant and the second coolant.However, because each of the channels are independent and can be can beconnected in any suitable way, any desired ratio may alternatively beused. In particular, channel designs that incorporate channels ofdifferent sizes, such as in the channel design of FIG. 5, may beparticularly well-suited for providing multi-mode cooling where thechannels are architected using additive manufacturing to provide anydesired ratio.

Additionally, any combination of coolants may be used in a multi-modeheat exchanger designed in accordance with some embodiments. Theinventors have recognized and appreciated that heat exchangers are oftenused in applications where multiple cooling modes, such as asteady-state cooling mode and a transient cooling mode, would be usefulbecause the component being cooled generates occasional spikes of heat.For example, some electronics components with a short-term high-dutycycle may generate transient heat spikes that may be more effectivelycooled using a phase-change material coolant than a fluid coolant.Accordingly, some embodiments are designed to incorporate differenttypes of coolants that allow the heat exchanger to provide differentmodes of cooling. For example, a heat exchanger that includes both afluid coolant (e.g., air, water) and a phase change material coolant(e.g., paraffin that changes state between a solid and a liquid) mayprovide both steady state cooling using the fluid coolant channels andtransient cooling using the phase change material coolant channels toeffectively provide cooling for a component or components that generateboth steady state heat and occasional, transient, spikes in heat.

FIG. 9 illustrates the exterior of a heat exchanger 900 in accordancewith some embodiments. Heat exchanger 900 includes a first inlet 910 anda first outlet 912 through which a first coolant (e.g., air) iscirculated. Heat exchanger 900 also includes a second inlet 920 and asecond outlet 922 through which a second coolant (e.g., water) iscirculated. FIG. 10 shows an alternate view of heat exchanger 900 inwhich the inlets and outlets are labeled. FIG. 11 shows a cross-sectionthrough heat exchanger 900 revealing heat exchanger channels 1110, 1112,1114 formed within the heat exchanger.

The channel design of heat exchanger 900 shown in FIG. 11 is similar tothe channel design discussed above in connection with FIG. 8 andincludes large diamond-shaped channels 1110, upper triangle channels1112, and lower triangle channels 1114.

The heat exchanger channels of heat exchanger 900 may be connected inany suitable way to direct the flow of the multiple coolants through theheat exchanger in a desired manner, as discussed in more detail below.FIGS. 12A and 12B schematically illustrate a manifold flow 1210, 1220 ofa first coolant F₁ and a second coolant F₂, respectively, through heatexchanger 900 in accordance with some embodiments. As shown in FIG. 12A,coolant F₁ enters inlet 910 and is directed to flow through multiplechannels of the heat exchanger. When reaching the end of the heatexchanger opposite the inlet 910, the manifold directs coolant F₁ to theother side of the heat exchanger where the coolant is distributed toflow through multiple channels of the heat exchanger toward outlet 912,where coolant F₁ exits the heat exchanger. Similarly, FIG. 12B shows themanifold flow 1220 tracing the flow from inlet 920 to outlet 922. Itshould be appreciated that the manifold flows shown in FIGS. 12A and 12Bare provided merely for illustration and any other suitable flow ofcoolant in heat exchangers designed in accordance with embodiments maybe used.

FIG. 13 shows an alternate view of heat exchanger 900 in which mountingstructures 630 are shown attached to the heat exchanger. A plurality ofchannels 1310 of different shapes and sizes formed within heat exchanger900 are also shown. FIG. 14 shows a side-view cross-section of heatexchanger 900 in which the coolant channels are more clearly shown. Thechannel pattern design shown in FIG. 14 is similar to the channelpattern shown in FIG. 5, and described above. In particular, the channelpattern shown in FIG. 14 includes a lower triangle channel 1410, twomiddle triangle channels 1412, 1414, a smaller diamond-shaped channel1416 formed in a layer above middle triangle channels 1412, 1414, and asmaller triangle channel 1418 formed in a layer above diamond-shapedchannel 1416, where the smaller triangle channel 1418 is partiallyfilled with a solid material to form a substantially flat surface 1420.To reduce the weight of the heat exchanger, additional diamond-shapedchannels 1422 are formed in triangle channels 1418. Althoughdiamond-shaped channels 1422 are described herein as performing afunction of reducing weight of the heat exchanger, it should beappreciated that in some embodiments channels 1422 may also be used forcooling by having a coolant provided therein. FIG. 15 shows an alternateview of heat exchanger 900 in which the heat transfer channels and themounting structures 630 are shown.

FIG. 16A shows an alternate design for a heat exchanger 1600 inaccordance with some embodiments. Heat exchanger 1600 includes aplurality of channels 1610 formed within an external structure 1620.FIG. 16B shows an alternate view of heat exchanger 1600 in which theexternal structure 1620 has been removed to provide a more detailed viewof channel structure 1610. In the implementation shown, channelstructure 1610 has been designed to maximize component surface areawhile minimizing the component volume. It should be appreciated, howeverthat any other channel design may alternatively be used.

FIG. 16C. shows a cross section through heat exchanger 1600 in which thecoolant channels in channel structure 1610 are more clearly shown.Although not shown, in some embodiments, one or more of the channels ofchannel structure 1610 may be filled with solid material to form anupper interface control surface, as discussed above.

Some embodiments are directed to a method of manufacturing a heatexchanger using an additive manufacturing process. FIG. 17 shows aflowchart of a process 1700 for manufacturing a heat exchanger inaccordance with some embodiments. In act 1710, a design for the heatexchanger is specified. The design may include the design of theone-piece body of the heat exchanger including any coolant inlets oroutlets, one or more mounting structures, the design of the coolantchannels, or any other suitable design features for structuralcomponents of the heat exchanger. A computer-aided design (CAD) programor other suitable software may be used to determine the design for theheat exchanger, and embodiments are not limited in how the design isspecified.

The process then proceeds to act 1712, where the heat exchanger isfabricated using an additive manufacturing process, as described above.A 3D printer or other suitable apparatus for additive manufacturingproduces layers of material (e.g., metal alloy) to fabricate the heatexchanger based on the specified design. The process then proceeds toact 1714, where the fabricated heat exchanger is tested for structuraldefects. Any suitable testing method including, but not limited to,using computed tomography (CT) may be used to test the components of theheat exchanger, and embodiments are not limited in this respect.

Having thus described several aspects of some embodiments of thisinvention, it is to be appreciated that various alterations,modifications, and improvements will readily occur to those skilled inthe art.

Such alterations, modifications, and improvements are intended to bepart of this disclosure, and are intended to be within the spirit andscope of the invention. Accordingly, the foregoing description anddrawings are by way of example only.

Various aspects of the present invention may be used alone, incombination, or in a variety of arrangements not specifically discussedin the embodiments described in the foregoing and is therefore notlimited in its application to the details and arrangement of componentsset forth in the foregoing description or illustrated in the drawings.For example, aspects described in one embodiment may be combined in anymanner with aspects described in other embodiments.

Also, the invention may be embodied as a method of manufacturing a heatexchanger, of which an example has been provided. The acts performed aspart of the method may be ordered in any suitable way. Accordingly,embodiments may be constructed in which acts are performed in an orderdifferent than illustrated, which may include performing some actssimultaneously, even though shown as sequential acts in illustrativeembodiments.

The phrase “and/or,” as used herein, should be understood to mean“either or both” of the elements so conjoined, i.e., elements that areconjunctively present in some cases and disjunctively present in othercases. Multiple elements listed with “and/or” should be construed in thesame fashion, i.e., “one or more” of the elements so conjoined. Otherelements may optionally be present other than the elements specificallyidentified by the “and/or” clause, whether related or unrelated to thoseelements specifically identified. Thus, as a non-limiting example, areference to “A and/or B”, when used in conjunction with open-endedlanguage such as “comprising” can refer, in one embodiment, to A only(optionally including elements other than B); in another embodiment, toB only (optionally including elements other than A); in yet anotherembodiment, to both A and B (optionally including other elements); etc.

As used herein in, the phrase “at least one,” in reference to a list ofone or more elements, should be understood to mean at least one elementselected from any one or more of the elements in the list of elements,but not necessarily including at least one of each and every elementspecifically listed within the list of elements and not excluding anycombinations of elements in the list of elements. This definition alsoallows that elements may optionally be present other than the elementsspecifically identified within the list of elements to which the phrase“at least one” refers, whether related or unrelated to those elementsspecifically identified. Thus, as a non-limiting example, “at least oneof A and B” (or, equivalently, “at least one of A or B,” or,equivalently “at least one of A and/or B”) can refer, in one embodiment,to at least one, optionally including more than one, A, with no Bpresent (and optionally including elements other than B); in anotherembodiment, to at least one, optionally including more than one, B, withno A present (and optionally including elements other than A); in yetanother embodiment, to at least one, optionally including more than one,A, and at least one, optionally including more than one, B (andoptionally including other elements); etc.

Having thus described several aspects of at least one embodiment of thisinvention, it is to be appreciated various alterations, modifications,and improvements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis disclosure, and are intended to be within the spirit and scope ofthe invention. Accordingly, the foregoing description and drawings areby way of example only.

What is claimed is: 1-13. (canceled)
 14. A method of manufacturing aheat exchanger, the method comprising: forming, using an additivemanufacturing process, a one-piece body and a plurality of channelsformed therein, wherein at least some of the plurality of channels forma lattice having layers of repeating shapes in a first dimension of theone-piece body, wherein the repeating shapes of the lattice havesuccessively-smaller dimensions across the layers in the first dimensionof the one-piece body.
 15. The method of claim 14, further comprisingfilling at least one of the plurality of channels with a phase changematerial.
 16. The method of claim 14, wherein forming the one-piece bodycomprises forming at least one mounting structure as a portion of theone-piece body.
 17. The method of claim 14, further comprising forming aplurality of structures adjacent to the lattice, wherein the pluralityof structures form an interface control surface.
 18. The method of claim17, further comprising forming a channel in at least some of theplurality of structures to reduce a weight of the heat exchanger.
 19. Amethod of cooling a component with a heat exchanger, the methodcomprising: arranging the heat exchanger adjacent to the component,wherein the heat exchanger comprises a plurality of channels, wherein atleast some of the plurality of channels form a lattice having layers ofrepeating shapes in a first dimension of the heat exchanger, wherein therepeating shapes of the lattice have successively-smaller dimensionsacross the layers in the first dimension.
 20. The method of claim 19,further comprising: circulating a fluid through the a first set of theplurality of channels and/or a second set of the plurality of channelsto provide operation of the heat exchanger in the first cooling mode andthe second cooling mode respectively.